This is tale of Billy Lenz born during the Christmas of 1970, who as a child was abused by his mother. Due to suffering from Jaundice because of a liver defect, making him a freak ''in the eyes of his mother'' (''who only saw the husband she'd come to despise when she looked at her son''). All she gave him was beatings, neglet and ridicle, while only his father ever showed him love, carering, comfort and compassion. Billy never got a single gift from his mother during X-mas (or his Birthday), and all the while her husband raised their son, she was cheating on Billy's father. But one christmas night in 1975, Miss Lenz gave her offspring a gift...the cruelist gift of all, when Billy (who was only five at the time) saw his beloved father die violently, as she and her lover battered Mr Lenz with claw hammer so fiercely that his eyes fell out, before locking Billy away in the attic—for good (for what he'd seen), while she was with her lover set about starting a "new" family...without him (having burried Mr. Lenz under the house). As Billy's mother fell pregnant with a daughter and treated her with love, which Billy had never experienced with his mother. His only contact with her came from his punishments she gave him for his lack of discipline. One night, now crazed with rage, Billy came out of the attic on his sister's eight birthday and brutally murdered his mother and her lover, treating them to similar fates as the one his father met (with the aid of a rolling pin and a spiked implement), before turning his anger on his own sister (leaving her as disfigured as he was), before local police managed to force there way in and drag him off to mental institute and his sister to a foster home, now minus one eye. Cut to present day, a group of nine sorority sisters consisting of Kelli (Katie Cassidy), Dana (Lacey Chabert), Lauren (Crystal Lowe), Megan (Jessica Harmon), Claire (Leela Savasta), Heather (Mary Elizabeth Winstead), Megan (Jessica Harmon), Melissa (Michelle Trachtenberg) and Eve (Kathleen Kole) along with their house mother (Andrea Martin) and Claire's older sister Leigh, who now live in Billy's childhood home, find themselves being harassed by threatening and intimidating mystery phone-calls during Christmas Break and as one of the girls goes missing, the girls begin being murdered one by one! Could Billy really have escaped and managed to make his back to his home? Or is someone else who may've lived there before them?